Transport in animals

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Transport in animals
Why we need a transport system?
3 week old larval anchovy
How big can you be and still meet O2 demand of
tissue simply by diffusion? The larval anchovy
(average body radius 0.6 mm) can meet all of
its metabolic demand by uptake of O2 by
diffusion. The respiratory and circulatory
systems will take over to supply O2 to the
tissues. Any animal larger than 1 mm cannot rely
on diffusion alone.
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Gases diffuse far more readily through gas than
aqueous solutions
Radius (distance to the geometric body center)
increases proportionally to body size. Again,
any animal with a body (made of water) radius gt 1
mm cannot obtain (or release) gases simply by
diffusion, so you need a circulatory system and a
medium in that system, i.e. blood.
Length 2 Radius 0.5
Length 4 Radius 1
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Why have blood?
Transport of nutrients from digestive tract to
tissues, to and from storage organs Transport of
metabolites (e.g., lactic acid from muscle to
liver) Transport of excretory products from
tissues to excretory organs Transport of
gases respiratory organs to/from
tissues Transport of hormones
Transport of cells including cells of
nonrespiratory function (e.g., leukocytes in
verts, numerous cell types in inverts) Transport
of heat Transmission of force e.g., locomotion
(earthworms, spiders), erection of
penis Coagulation
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Open vs Closed Circulation
Open circulatory system is characteristic of
many inverts. Blood (hemolymph) empties into
hemocoel and bathes tissues and organs
directly Low pressure, high volume (up to 40 of
body mass) Animal typically has hard shell or
exoskeleton. Insects have an open circulatory
system, but do not use it for oxygen transport.
Closed circulatory system is found in all
vertebrates and some inverts (e.g.,
cephalopods). Blood remains in
vessels capillaries allow close contact between
blood and tissues Arterial system high
pressure, takes blood away from heart Low volume
(5-10 of body mass)
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Mass flow transport

• Needed for a constant supply of
• Oxygen
• Nutrients
• Also needed to get rid of waste products such as
• Carbon

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3 Major Parts of the Circulatory system
Blood Vessels - routes blood travels Heart
pumps or pushes blood through body Blood
carries important stuff through body
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head, neck and arms
superior vena cava
pulmonary vein
lungs
pulmonary artery
aorta
right atrium right ventricle
left atrium left ventricle
inferior vena cava
hepatic artery
hepatic vein
liver
hepatic portal vein
mesenteric artery
gut
renal vein
renal artery
kidneys
body and legs
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The Heart
The heart is mainly made of cardiac muscle, each
muscle cell is joined to the next by an
intercalary disc. These cells are myogenic,
this means they can contract and relax of their
own accord throughout a human life
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superior vena cava
aorta
left pulmonary artery
right pulmonary artery
pulmonary veins
pulmonary veins
right atrium
left atrium
bicuspid valve
tricuspid valve
left ventricle
right ventricle
septum
inferior vena cava
semi-lunar valves
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Your Blood is made of
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Plasma
Plasma- water, ions, proteins Plasma
proteins albumin- provides osmotic
pressure globulins- alpha and beta-
transport gamma- antibodies (produced
by lymphocytes other proteins by
liver) fibrinogen- clotting Plasma volume
regulated by hormones like ADH
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Formed Cells
Erythrocytes- (red blood cells) no nuclei or
mitochondria circulate for about 120 days 280
million hemoglobin molecules per cell Leukocytes
(white blood cells) granular and
agranular granular neutrophils, eosinophils,
basophils agranular lymphocytes,
monocytes capable of amoeboid movement Platelets
- involved in clotting
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ATRIAL SYSTOLE - Heart
The Cardiac Cycle
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END OF PRESENTATION!